Back pressure valve for drill pipe testing



May 23, 1933? H. B, ZIEGLER BACK PRESSURE VALVE FOR DRILL PIPE TESTINGFiled Sept. 19, 1932 Haro/a7 5. Zz'ey/e z" INVENTOR ATTOR N EY PatentedMay 23, 1933 vUm'rlan s'rArEs PATENT OFFICE HABOLDRQZIEQLER, 0F SHAWNEEOKLAHOMA, ASSIGNIOR OF ONE-HALF TO DELL `BAKER, OF SHAWNEE, OKLAHOMA Y IBACK PRESSURE FOR DRILL PIPE TESTING y Application illed September 19,1932. Serial N o. 693,913.

The object of the invention is to provide a back pressure valveparticularly adapted for application to the lower extremity of well pipewhen -lowerin the same into a Well or Huid filled drill ole, so thatthere may be prevented the entrance of any fluid into the pipe prior toits reaching the bottom or rat hole shoulder; to provide a back pressurevalve which may be readily released on imparting a slight angular orturning movement to the 'drill pipe after the latter has reached bottom;and generally to provide a valve of the kind indicated which is ofsimple form and susceptible of cheap manufacture. g

`With this object in view, the invention consists in a construction andcombination of parts of which a preferred embodiment is illustrated inthe accompanying drawing Ibut to which embodiment the invention is notto be restricted. Continued use in practice may dictateV certain changes0r alterations and the right is claimed to make any which fall withinthe scope of the annexed claims. x

In the drawing:

Figure 1is a; central vertical sectional view of the invention. Y,

Figure 2. is an exterior -elevational view.

Figure 3 is a sectional' view on the plane indicated by the line 3 3 ofFigure 1'.

The valve 10 constituting the invention is formed with a conicalterminal 11 arranged to engage a replaceable seat ring 12,-the latterbeing carried in the lower end of a bushing 14 which is mounted in theupper end .of the valve mandrel 15, having a threaded engagement withthe latter asindicated at The valve A 10 is reduced in crossv section asrespects the bore of the mandrel 15` but at its lower end is'enlarged asindicated at 17 to provide ashouldered portion. which lits snugly in themandrel but slides freely in the same. The shouldered portion, thusYkeeps the valye aligned for engagement with its seat. r

'The valve is formed with a longitudinal bore 18 openingen the undenside of the shouldered portion and extending close to Mounted in themandrel and extending through suitable openings in diametricallyopposite sides of the lWall thereof are the valve 'releasing dogs 20,these dogs -being of curved form with their noses 21 bearing on the topface of the shouldered portion 17 and when the valve is seated againstthe seat ring 12, the heel portions 22 of the dogs project beyond theperiphery of the manrel.

The valve is held yieldingly on its Seat through the instrumentality ofa coil spring 23, the latter being wound to it the bore ofthe mandreland having the one end abutting the under face of the shouldered portionand the other end abutting the upper end of a nipple 24, threadinglyengaged with the bore of the mandrel as indicated at 25.

The mandrel at the .upper end is connected with the lower end of abushing 26' designed to be mounted at the lower end of e' `lower end ofthe mandrel 1 5, thebushing 28 having the corner of vits bore rounded asindicated at 29 and being provided on the upper end with a seal lring30, made preferably of lead .and seated in a recess formed vin the endof the bushing. Provision is made for positively tconn'ecting themandrel 15 with the bushing 28 or releasing it therefrom and thisprovision resides in a coupling ring .31 interiorly threaded to be enlgaged with areduced extremity 32 oflthe valve mandrel and brought intoabutting engagement with the shoulder 33 on the mandrel. The threadeffecting connection between the coupling ring'an'd the mandrel. 1srelatively fine. Exteriorly, however, thecoupling ring is formed with acoarse thread 34, the ring being of frusto-conical shape exteriorly andsaid4 coarse ,thread being formed on this exterior surface to engage acorrespondingly formed thread arranged in a conically formed counterborein the lower end of the bushing 28.

The bushing 26 is connected to the lower end of the lowermost length ofpipe being lowered into a well or drill holeand when thel coupling ring31 is. engaged with the threaded counterbore of the bushing 28, relativemovement between the mandrel and the bushing 28 is precluded and thevalve 10 is held yieldingly in engagement with its seat ring through theaction` of the spring 23. The pipe can thus be readil lowered in thewell without the creation o any back pressure in the same, sincethelower end` is ei'ectively closed by the action ofy the valve. When thepipe reaches the bottom of the hole, however, the housing abuts thebottom and the valve may then be opened by imparting a slight angular orturning movement to the length of pipepfrom the exterior surface, thismovement resulting in releasing the coupling ring from the` bush-l ing28 by unscrewing it from the latter. Since the housing 27 can descend nofurther, the release of the coupling ring will permit the string of pipeby itsweight to move the mandrel 15 axially down through the bushing 28,when the tail portions of the dogs 2O abut the rounded edge 29' thusrocking the dogs inwardly and forcing their noses 21 downwardly which,by reason oi engaging the shoulder of the valve, depress itfromlengagement with the seat rin 12. The tail portions of the dogs maypass within the bore of the bushing 28 an'd the mandrel be thus lowereduntil the lower end of the bushing 26 engages the sealing member 30,which is' preferably of lead, and

, prevents the entrance of any fluid at this point. Fluid may enter thepipe, however, when the valve is opened in the manner aforesaid, flowinup through the nipple 24 and, through the bore 18 of the valve, thenceout through the ports 19 and around the nose of the valve through thebushing 14 and bushing 26 into .the pipe.

The'device is particularly serviceable in -sand testing operations, whenthe empty drill pipe is lowered in the fluid filled hole and the valveopened-as aforesaid.

Ports or openings 35 are provided in the mandrel in the region of thedogs 20 and theseare especially useful in the sand test; ing operation,as they allow fluid to pass through the mandrel and equalize thehydrostatic pressure above and below the packer, permitting the packerto be removed from its seat with much less pull than is ordi-` narily reuired. n

While t e opening movement of the valve is imparted by releasing themandrel from its engagement with the bushing 28, closing movement isautomatically effected when the device is withdrawn, since the bushing28 and connected housing 27 will not follow the upward movement of themandrel until the latter has been raised to the point where the couplingring engages the counterbore, when the dogs 20yare free kof the bushing28 and the spring 23 may. function to seat the valve.

The invention having been described, what is claimed as new and usefulis: Y

1. A back pressure valve for terminal application. to a string of pipecomprising a hollow mandrel, a ported member carried at the upper end ofthe mandrel, a valve slidably mounted in the mandrel, a springyieldingly impelling'the valve onto a seat formed on said ported memberto close communication through the port, means for 'securing the mandrelto the string of pipe, a member with which the mandrel is detahablyconnected, and means carried by the mand 'el and engageable with saidmember to unseat said valve when the mandrel is released from saidmember.v f Y Y 2. A back pressure valve for terminal application to astring of pipe comprising a hollow mandrel, a orted member carried atthe upper end o the mandrel, a valve plication` to a string of pipecomprising a hollow mandrel, a orted member carried at the upper end o?slidably mounted in the mandrel, a spring yieldingly impelling the valveonto a seat formed on said ported member to close communication throughthe port, means for se- 'curing the mandrel to the string of pipe, ahousing `disposed in surrounding relation to the mandrel at the vlowerend, al bushing coupled to said housing, a releasable couplingconnecting the .mandrel to the bushing, and means carried by the mandreland engageable with said bushing to unseat'the valve when the mandrel isreleased from said bushing, said means comprisingrockably mounted ldogsextending through openings in the mandrel and having noses bearing onthe valve and heel portions extending beyond the periphery of theman'dreh 4. A back pressure valve forterminal application to a string ofpipe comprising a the mandrel, a valve hollow mandrel, a ported membercarried released from the last said bushing and at the upper endyieldingly'vimpelling the valve onto a seat 5 formed on said portedmember to close communication through the port, means-for securing themandrel to the string o pipe, a housing disposed in surrounding relationto the mandrel at the lower end, a bushing coupled to said housing, areleasable coupling connecting the mandrel to the bushing, and meanscarried b the mandrel and engageable with said bus ing to unseat thevalve when the mandrel `is released from said bushing, said meanscomprising rockably mounted do s extending through openings in the manrel and having noses bearing on the valve and heel portions extending`/beyond the periphery of the mandrel, and

said bushin being rounded on its upper inner edge or camming actionagainst the heel portions of said dogs.

the mandrel, a valve lowered therethrough. slidably mounted in themandrel, a spring ture.

5. A back pressure valve for terminal application to a string of pipecomprisin 'a hollow mandrel, a ported member carrie at the upper end ofthe mandrel, a valve slidably mounted inthe mandrel, a spring yieldinglyimpelling the valve onto a seat formed on said ported member to closecommunication through the port, means for securing the mandrel to thestring of ipe, a housing disposed in surrounding rela'tlon to themandrel at the lower end, a bushing coupled to i \said housing, areleasable cou ling connecting the mandrel to thebushi g, and meansvcarried by the mandrel -and engageable with said bushing to unseat thevalve when the mandrel is released from said bushing, said releasablecouplin comprising a ring 40 threadingly engage with the lower end oisaid mandrel and formed exteriorly with a coarse thread engageable inthe lower end of said bushing to be released therefrom by an angular orturning movement'imparted to said mandrel.

6. A back pressure valve for terminal application to a string of pipecomprising a hollow mandrel, an exterior bushing at the upper end of thesame for connection to the lower end of the string of pi e, an interiorbushing inthe 'upper end o the mandrel and formed with a valve seat atits lower end, a valve slidably mounted in the mandrel, -a springyieldingly impelling the valve onto said seat, a bushlng in surroundingre- 'lation to the mandrel at the lower end, a coupling member couplingsaid bushing' to the mandrel to permit its release therefrom whendesired, valve releasing dogs mounted in the mandrel and effective tounseat the valve by engagement with the last said bushing vwhen themandrel is released therefrom and a seal rino` mounted in the upper endof the last said lbushing for engagementwith A 05 the first said bushingwhenzthe. mandrel is In testimony whereof he aixes his` signaioo ias

